Financial Instruments (Derivative Instruments Notional Amounts Outstanding) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Interest Rate Swaps [Member]
Notional Amount Of Derivative	$ 116,209	$ 116,209
Forward Currency Contracts [Member]
Notional Amount Of Derivative	$ 212,700	$ 141,050